# /// script
# dependencies = [
#     "transformers>=5.0.0rc1",
#     "peft>=0.14.0",
#     "torch>=2.0.0",
#     "accelerate>=0.24.0",
#     "huggingface_hub>=0.20.0",
#     "sentencepiece>=0.1.99",
#     "protobuf>=3.20.0",
#     "numpy",
#     "gguf",
#     "safetensors",
#     "pillow",
#     "unsloth @ git+https://github.com/unslothai/unsloth.git",
#     "unsloth_zoo",
#     "xformers",
# ]
# ///

"""
GGUF Conversion Script for Vision/Multimodal Models

Creates both model.gguf and mmproj-model.gguf files for vision models.

Environment variables:
- MODEL_PATH: The model to convert (full model or LoRA adapter)
- BASE_MODEL: Base model for LoRA merge (optional, only for LoRA adapters)
- OUTPUT_REPO: Where to upload GGUF files
- MODEL_NAME: Name prefix for output files
- IS_LORA: "true" if this is a LoRA adapter, "false" for full model
"""

import os
import torch
from transformers import AutoModel, AutoTokenizer, AutoProcessor
from huggingface_hub import HfApi, hf_hub_download, login

# Get HF_TOKEN for private repo access
HF_TOKEN = os.environ.get("HF_TOKEN")
if HF_TOKEN:
    print(f"HF_TOKEN found (length: {len(HF_TOKEN)})")
import subprocess
import shutil
import glob

print("=" * 60)
print("GGUF Conversion Script for Vision/Multimodal Models")
print("=" * 60)

# Configuration
MODEL_PATH = os.environ.get("MODEL_PATH")
BASE_MODEL = os.environ.get("BASE_MODEL", "")
OUTPUT_REPO = os.environ.get("OUTPUT_REPO")
MODEL_NAME = os.environ.get("MODEL_NAME")
IS_LORA = os.environ.get("IS_LORA", "false").lower() == "true"

print(f"\nConfiguration:")
print(f"  Model path: {MODEL_PATH}")
print(f"  Base model: {BASE_MODEL}")
print(f"  Output repo: {OUTPUT_REPO}")
print(f"  Model name: {MODEL_NAME}")
print(f"  Is LoRA: {IS_LORA}")

# Step 1: Load model (with optional LoRA merge)
print("\n[1/7] Loading model...")

merged_dir = "/tmp/merged_model"
os.makedirs(merged_dir, exist_ok=True)

if IS_LORA:
    import json

    print(f"  Loading model with LoRA adapter...")
    print(f"  Base model: {BASE_MODEL}")
    print(f"  Adapter: {MODEL_PATH}")

    model = None
    tokenizer = None

    # Try unsloth first (best for unsloth-trained adapters)
    try:
        print("  Trying unsloth FastModel...")
        from unsloth import FastModel
        model, tokenizer = FastModel.from_pretrained(
            model_name=MODEL_PATH,
            dtype=torch.float16,
            load_in_4bit=False,
            token=HF_TOKEN,
        )
        print("  Loaded with unsloth FastModel")

        # Merge and save
        print("  Merging LoRA weights...")
        model.save_pretrained_merged(merged_dir, tokenizer, save_method="merged_16bit")
        print(f"  Merged model saved to {merged_dir}")
        model = None  # Free memory
    except Exception as e:
        print(f"  Unsloth failed: {e}")
        print("  Falling back to manual LoRA weight application...")

        # Manual approach: load base model, then manually apply LoRA weights
        from peft import LoraConfig, get_peft_model
        from safetensors.torch import load_file

        # Download adapter weights
        adapter_weights_path = hf_hub_download(MODEL_PATH, "adapter_model.safetensors", token=HF_TOKEN)
        adapter_config_path = hf_hub_download(MODEL_PATH, "adapter_config.json", token=HF_TOKEN)

        with open(adapter_config_path) as f:
            adapter_config = json.load(f)

        # Load base model with specific class - detect from model name
        model_classes = []
        base_lower = BASE_MODEL.lower()
        if "ministral" in base_lower or "mistral" in base_lower:
            model_classes = [
                ("Mistral3ForConditionalGeneration", "transformers"),
                ("AutoModelForCausalLM", "transformers"),
            ]
        elif "glm" in base_lower:
            model_classes = [
                ("Glm4vForConditionalGeneration", "transformers"),
                ("AutoModelForVision2Seq", "transformers"),
            ]
        elif "gemma" in base_lower:
            model_classes = [
                ("Gemma3ForConditionalGeneration", "transformers"),
                ("AutoModelForVision2Seq", "transformers"),
            ]
        else:
            model_classes = [
                ("AutoModelForCausalLM", "transformers"),
                ("AutoModelForVision2Seq", "transformers"),
            ]

        print(f"  Detected model type, trying: {[c[0] for c in model_classes]}")

        base_model = None
        for class_name, module in model_classes:
            try:
                import importlib
                mod = importlib.import_module(module)
                model_class = getattr(mod, class_name)
                print(f"  Trying {class_name}...")
                base_model = model_class.from_pretrained(
                    BASE_MODEL,
                    torch_dtype=torch.float16,
                    device_map="cpu",  # Load on CPU first
                    trust_remote_code=True,
                    token=HF_TOKEN,
                )
                print(f"  Base model loaded with {class_name}")
                break
            except Exception as e2:
                print(f"  {class_name} failed: {e2}")
                continue

        if base_model is None:
            raise ValueError(f"Could not load base model {BASE_MODEL}")

        # Load adapter weights
        print("  Loading adapter weights...")
        adapter_weights = load_file(adapter_weights_path)

        # Apply LoRA weights manually
        print("  Applying LoRA weights to base model...")
        lora_alpha = adapter_config.get("lora_alpha", 16)
        lora_r = adapter_config.get("r", 8)
        scaling = lora_alpha / lora_r

        state_dict = base_model.state_dict()
        for key, value in adapter_weights.items():
            # LoRA weights are named like: base_layer.lora_A.weight, base_layer.lora_B.weight
            if "lora_A" in key:
                base_key = key.replace(".lora_A.weight", ".weight").replace("base_model.model.", "")
                lora_b_key = key.replace("lora_A", "lora_B")
                if lora_b_key in adapter_weights and base_key in state_dict:
                    lora_a = value
                    lora_b = adapter_weights[lora_b_key]
                    # Merge: W = W + scaling * B @ A
                    delta = scaling * (lora_b @ lora_a)
                    state_dict[base_key] = state_dict[base_key] + delta.to(state_dict[base_key].dtype)

        base_model.load_state_dict(state_dict)
        print("  LoRA weights applied")

        # Save merged model
        base_model.save_pretrained(merged_dir, safe_serialization=True)
        del base_model

    # Load and save tokenizer/processor from adapter (has chat template)
    # Try adapter first, then base model
    print("  Saving processor/tokenizer...")
    processor_saved = False
    for source in [MODEL_PATH, BASE_MODEL]:
        try:
            processor = AutoProcessor.from_pretrained(source, trust_remote_code=True, token=HF_TOKEN)
            processor.save_pretrained(merged_dir)
            print(f"  Processor saved from {source}")
            processor_saved = True
            break
        except Exception as e:
            print(f"  Could not load processor from {source}: {e}")

    if not processor_saved:
        for source in [MODEL_PATH, BASE_MODEL]:
            try:
                tokenizer = AutoTokenizer.from_pretrained(source, trust_remote_code=True, token=HF_TOKEN)
                tokenizer.save_pretrained(merged_dir)
                print(f"  Tokenizer saved from {source}")
                break
            except Exception as e:
                print(f"  Could not load tokenizer from {source}: {e}")

    # Copy chat template if exists in adapter
    try:
        chat_template_path = hf_hub_download(MODEL_PATH, "chat_template.jinja", token=HF_TOKEN)
        shutil.copy(chat_template_path, f"{merged_dir}/chat_template.jinja")
        print("  Copied chat_template.jinja from adapter")
    except:
        pass
else:
    print(f"  Loading full model: {MODEL_PATH}")
    # For full models, download directly to merged_dir
    from huggingface_hub import snapshot_download
    snapshot_download(
        repo_id=MODEL_PATH,
        local_dir=merged_dir,
        local_dir_use_symlinks=False,
        token=HF_TOKEN,
    )
    print(f"  Model downloaded to {merged_dir}")

torch.cuda.empty_cache()
print("  Model prepared")

# List contents of merged dir
print(f"\n  Contents of {merged_dir}:")
for f in sorted(os.listdir(merged_dir))[:15]:
    print(f"    {f}")

# Step 2: Install build tools and clone llama.cpp
print("\n[2/7] Setting up llama.cpp...")
subprocess.run(["apt-get", "update", "-qq"], check=True, capture_output=True)
subprocess.run(["apt-get", "install", "-y", "-qq", "build-essential", "cmake"], check=True, capture_output=True)
print("  Build tools installed")

if os.path.exists("/tmp/llama.cpp"):
    shutil.rmtree("/tmp/llama.cpp")
subprocess.run(
    ["git", "clone", "--depth", "1", "https://github.com/ggml-org/llama.cpp.git", "/tmp/llama.cpp"],
    check=True, capture_output=True
)
print("  llama.cpp cloned")

subprocess.run(["pip", "install", "-q", "-r", "/tmp/llama.cpp/requirements.txt"], check=True, capture_output=True)
print("  Python dependencies installed")

# Step 3: Convert to GGUF with mmproj (FP16)
print("\n[3/7] Converting to GGUF format with multimodal projector...")
gguf_output_dir = "/tmp/gguf_output"
os.makedirs(gguf_output_dir, exist_ok=True)

convert_script = "/tmp/llama.cpp/convert_hf_to_gguf.py"
gguf_fp16 = f"{gguf_output_dir}/{MODEL_NAME}-f16.gguf"

# Convert with --mmproj to generate vision projector
print("  Running conversion with --mmproj...")
result = subprocess.run(
    ["python", convert_script, merged_dir, "--outfile", gguf_fp16, "--outtype", "f16", "--mmproj", merged_dir],
    capture_output=True, text=True
)
print(result.stdout)
if result.stderr:
    print("STDERR:", result.stderr)

if result.returncode != 0:
    print("  Warning: mmproj conversion may have failed, trying without...")
    result = subprocess.run(
        ["python", convert_script, merged_dir, "--outfile", gguf_fp16, "--outtype", "f16"],
        check=True, capture_output=True, text=True
    )
    print(result.stdout)

print(f"  FP16 GGUF created")

# Find the mmproj file
mmproj_files = glob.glob(f"{gguf_output_dir}/mmproj*.gguf")
if not mmproj_files:
    # Check current directory too
    mmproj_files = glob.glob("mmproj*.gguf")
    if mmproj_files:
        # Move to output dir
        for f in mmproj_files:
            shutil.move(f, gguf_output_dir)
        mmproj_files = glob.glob(f"{gguf_output_dir}/mmproj*.gguf")

print(f"\n  Files in output dir:")
for f in os.listdir(gguf_output_dir):
    size_gb = os.path.getsize(f"{gguf_output_dir}/{f}") / (1024**3)
    print(f"    {f}: {size_gb:.2f} GB")

# Step 4: Build quantize tool
print("\n[4/7] Building quantize tool...")
os.makedirs("/tmp/llama.cpp/build", exist_ok=True)

subprocess.run(
    ["cmake", "-B", "/tmp/llama.cpp/build", "-S", "/tmp/llama.cpp", "-DGGML_CUDA=OFF"],
    check=True, capture_output=True, text=True
)
subprocess.run(
    ["cmake", "--build", "/tmp/llama.cpp/build", "--target", "llama-quantize", "-j", "4"],
    check=True, capture_output=True, text=True
)
print("  Quantize tool built")

quantize_bin = "/tmp/llama.cpp/build/bin/llama-quantize"

# Step 5: Create quantized versions
print("\n[5/7] Creating quantized versions...")
quant_formats = [
    ("Q4_K_M", "4-bit medium"),
    ("Q5_K_M", "5-bit medium"),
    ("Q8_0", "8-bit"),
]

quantized_files = []
for quant_type, desc in quant_formats:
    print(f"  Creating {quant_type} ({desc})...")
    quant_file = f"{gguf_output_dir}/{MODEL_NAME}-{quant_type.lower()}.gguf"
    result = subprocess.run([quantize_bin, gguf_fp16, quant_file, quant_type], capture_output=True, text=True)
    if result.returncode == 0:
        size_gb = os.path.getsize(quant_file) / (1024**3)
        print(f"    {quant_type}: {size_gb:.2f} GB")
        quantized_files.append((quant_file, quant_type))
    else:
        print(f"    {quant_type}: FAILED - {result.stderr}")

# Step 6: Upload to Hub
print("\n[6/7] Uploading to Hugging Face Hub...")
api = HfApi(token=HF_TOKEN)

# Upload all GGUF files
for f in os.listdir(gguf_output_dir):
    if f.endswith('.gguf'):
        filepath = f"{gguf_output_dir}/{f}"
        print(f"  Uploading {f}...")
        api.upload_file(
            path_or_fileobj=filepath,
            path_in_repo=f,
            repo_id=OUTPUT_REPO,
        )

# Step 7: Create model card entry
print("\n[7/7] Creating model info...")
info_content = f"""
## {MODEL_NAME}

Vision/Multimodal model converted to GGUF.

**Source:** {MODEL_PATH}
**Base:** {BASE_MODEL if BASE_MODEL else "N/A"}

### Files
- `{MODEL_NAME}-f16.gguf` - Full precision
- `{MODEL_NAME}-q8_0.gguf` - 8-bit quantized
- `{MODEL_NAME}-q5_k_m.gguf` - 5-bit quantized
- `{MODEL_NAME}-q4_k_m.gguf` - 4-bit quantized (recommended)
- `mmproj-*.gguf` - Vision projector (required for image input)

### Usage with llama.cpp
```bash
llama-mtmd-cli -m {MODEL_NAME}-q4_k_m.gguf --mmproj mmproj-{MODEL_NAME}-f16.gguf --image your_image.jpg
```
"""

# Append to README if exists
try:
    existing = api.hf_hub_download(OUTPUT_REPO, "README.md")
    with open(existing) as f:
        content = f.read()
    content += "\n" + info_content
except:
    content = f"# {OUTPUT_REPO.split('/')[-1]}\n\nGGUF model collection.\n" + info_content

api.upload_file(
    path_or_fileobj=content.encode(),
    path_in_repo="README.md",
    repo_id=OUTPUT_REPO,
)

print("\n" + "=" * 60)
print(f"CONVERSION COMPLETE: {MODEL_NAME}")
print(f"Repository: https://huggingface.co/{OUTPUT_REPO}")
print("=" * 60)